After a stroke, there is very little time for getting treatment, however, now certain patients have a little bit of more time. When a clot cuts off blood flow to parts of the brain is when a stroke occurs, and that part of the brain soon begins to die. Tissue plasminogen activator or tPA, a drug that helps dissolve clots and restores blood flow must be given as soon as possible after a stroke, as with every passing minute, more brain cells die.

However, it takes time to get a patient to hospital and the benefits of tPA treatment outweigh its very real risk of causing uncontrollable bleeding in the brain. Initially, on discovering tPA, it was thought there might be a six-hour window, however, U. S. clinical trials suggest and current recommendations discourage using tPA more than three hours after the onset of a stroke.

Last year, clinical trials in Europe found selected patients still benefitted from tPA up to four and a half hours after a stroke.

The American Heart Association has now issued an advisory formally spelling out which patients could benefit from later tPA treatment, but patients are warned not to misinterpret the statement.

Patients who should not receive tPA over three hours after a stroke:

" Patients aged 80-plus.
" Patients taking anti-coagulants i. e. blood thinning drugs.
" Patients with a history of stroke and diabetes

The new AHA advisory will appear in the August issue of the AHA journal Stroke.